Printing telegraph apparatus



Feb. 2, 1943. K. A. SYLVESTER 2,310,129

PRINTING TELEGRAPH APPARATUS Filed Aug. 22, 1941 FlG.1

INVENTOR. KIMMEL A. SYLVEST ER I 2 ATTORIGEY.

Patented Feb. 2, 1943 UNETED STATES nane PATENT OFFICE PRINTING TELEGRAPH APPARATUS Kimmel A. Sylvester, Skokie, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware 11 Claims.

' tems wherein a line relay is employed.

An object of this invention is to provide a simplified mounting arrangement for a demountable line relay eiiective to maintain continuity of the telegraph line upon the removal of the line relay.

Another object of this invention is to provide a simplified mechanism operable to establish a predetermined condition on the signal responsive apparatus upon the removal of the line relay which controls the printing telegraph apparatus.

In telegraph communication systems, a line relay may be connected in a telegraph line to control a signal responsive apparatus, such as a printing telegraph machine in accordance with code signal combinations received over the line, and in one such system, namely, the start-stop system, each code signal combination includes a plurality of code impulses and a plurality of control impulses. The control impulses are, generally, a start impulse, customarily a no-current condition of the line, which is effective to initiate the operation of the printing machine and a stop impulse, usually a current condition of the line, which arrests the printing machine at the completion of a code signal combination and holds the mechanism idle until the reception of the next succeeding start impulse.

It frequently becomes necessary to remove the line relay from electrical connection with the line in order to adjust its armature properly, and unless precautionary measures are taken, the removal of the line relay will open the line, resulting in the establishment of a no-current condition on the line, which is equivalent to a start impulse and which would initiate the operation of all the signal responsive apparatus on the line; and also would result in an interruption of service over the line due to its open condition. To obviate these undesirable results, it has been the practice in the past to provide a shunt to be applied manually about the relay prior to its removal so that line continuity is maintained. Failure to apply the shunt at the proper time, however, has caused many inconveniences because of the effect inherent in interrupting the line and the failure to remove the shunt after the relay has been returned to service has caused further inconveniences by rendering the relay inoperative.

For the purpose of maintaining line continuity so that the afore-mentioned operating difliculties and inconveniences may be eliminated, this invention features a line relay arrangement including an auxiliary circuit conditioned by the relay to close the line circuit as the relay is removed from service but before the relay is out of electrical connection with the line.

This invention also features a switch member operated by the line relay to disable the auxiliary or shunt circuit upon the return of the relay to service.

The signal responsive apparatus usually associated with telegraph systems of the type under consideration includes a selector magnet which is electrically connected to the line relay to be controlled thereby in accordance with received code signal combinations. Accordingly, when the line relay is removed from service and from electrical association with the selector magnet, the effect is the same as the receipt by the selector magnet of a start impulse which results in initiating the operation of the signal responsive apparatus. This false operation of the apparatus is undesirable and is eliminated by this invention.

As a further feature of this invention, therefore, the line relay arrangement includes an auxiliary circuit for the selector magnet of the signal responsive apparatus effective automatically to place and to maintain a predetermined condition on the selector magnet as the line relay is removed from service.

As a still further feature of this invention the line relay operates a switch member to disable the auxiliary circuit and establish a circuit connection between the line relay and selector magnet as the relay is returned into service.

The line relay arrangement of this invention includes a relay mounting plate having facilities to receive the demountable relay in plug and jack fashion, connecting the relay in the line circuit. A plurality of contact pairs is supported by the mounting plate operable normally; that is, when the relay is disassociated from the plate, to close an auxiliary circuit around the line relay terminals to close the line at the particular relay point and to close a circuit that applies a predetermined condition, such as marking condition, to the selector magnet of the signal responsive apparatus to maintain that apparatus in its idle condition. A switch plunger is carried by the plate and operated by the relay as it is inserted in the line to disable the auxiliary circuits, to close the line circuit through the relay, and to place the selector magnet in electrical connection with the relay. As the relay is removed from service, spring members of the contact pairs operate the switch plunger to restore the auxiliary circuit for the selector magnet and then the auxiliary circuit for the line terminal, these circuit conditions being established before the relay is removed from electrical connection with the line.

For a more complete understanding of this invention, reference may be had to the following detailed description, which is to be read in connection with the accompanying drawing, where- Fig. l is aplan view partly in section of a line relay arrangement embodying the features of this invention and showing the demountable relay in operative condition;

Fig. 2 is a View of the line relay arrangement of Fig. 1 showing the demountable relay removed from its operative position; and

Fig. 3 is a circuit diagram of the line relay arrangement of Fig. 1.

The mechanical features and details of the line relay arrangement which is the subject of this invention are illustrated in Figs. 1 and'2 wherein a mounting plate II is provided for supporting the line relay arrangement. A jack assembly I! is supported by plate H and is provided with terminals !3 to which the telegraph line and the other electrical circuits associated with the line relay arrangement may be connected. The demountable line relay l4 isprovided wih projecting contact'elements I6 so that when the relay is associated with the mounting plate, the contact elements I6 cooperating with the jack l2 will place the relay in electrical association with terminals l2 connectedto those circuits included in the present circuit arrangement in a manner to be hereinafter described. In order to support the relay M, the mounting plate I l is provided with a plurality of apertures 2, the resilient elements 24 of the contact pairs will have converged sufiiciently to cause the contact pairs 28 and 28 associated therewith to condition auxiliary circuits to be described herein- I1 into which projecting studs or supporting pins l8 secured to the relay base plate I9 may be inserted. ihe outward extremities of the supporting studs l8 are formed to engage and be held by spring detents 2| which lock the relay M in position.

A contact pile-up 22 removably supported on a bracket 23 which in turn is secured to mounting plate H includes a plurality of contact pairs for conditioning auxiliary circuits in a manner to be hereinafter described. Each contact pair includes an elongated member 24 of resilient material and each such element is formed into a cam-shaped projection 25 on its outward eX- tremity. The camprojections 25 of opposite springs 24 face one another and provide a space into which a switch operating plunger 26 is adapted to be projected for the purpose of opening the contact pa rs 28 and 29. The switch operating plunger 25 is provided with a cylindrical shank member slidably supported in an aperture located in mounting plate H and in bracket 23; and a head portion 21 which is substantially cone-shaped. Preferably this plunger is constructed of Bakelite but any other insulating material m ght be used. .When the demountable relay I4 is removed from the mounting plate l, the resilient elements 24 of the contact pairs are able throu h the engagement of their cam portions 25 which bear against the head 2'! of the plunger 26 to slide the plunger in a leftward direction as viewed in Fig. 1, until the head bears against the vertical section of bracket When the plunger has been shifted to its extreme leftward position as seen in Fig.

after. When in this position, the shank of the plunger 26 projects beyond the front face of the mounting plate I! so that as the relay hl is subsequently assembled into the mounting arrangement, the base plate l9 thereof will engage the leftward extremity of the plunger shank and move the plunger in a rightward direction as viewed in Fig. 1, inserting the head 27 between the cam surfaces of the resilient elements of the contact pairs, urging those elements divergently thus to open at the contact pairs the auxiliary circuits controlled thereby.

The resilient elements as of the individual contact pairs are symmetrical in configuration and length. and therefore abut against the same relative position on the head 2'! of the plunger 25 so that as the plunger is operated by the insertion and removal of the relay It, the contact elements are moved identical distances and the contact pairs would normally be opened and closed simultaneously. It has been found desirable, however, for a reason which will be pointed out in detail hereinafter, to open the contact pairs not simultaneously but in a predetermined sequence, and in order to obtain a sequential operation of the contact pairs, the spacing provided between the contact elements of the contact pairs are of diiierent lengths; for example. in 1 the spacing 23 of the contact elements comprising one contact pair is less than the spacing 29 of the contact elements comprising the other contact pair. With this constructon, as the resilient elements E l move the plunger 26 upon the removal of the line relay, the upper contact pair will be operated prior to the operation of the lower contact pair, thus providing a sequential operation of the contact pairs.

The length of the shank of plunger 2 is so proportioned with respect to the length of the contact elements it carried by the dernountable relay it that on associating the relay with the line, the contact elements 25 engage and come into electrical connection with the jack assembly l2 before the base plate 19 or" the relay engages plunger 26 and moves it in a rightward direction to disable the circuits closed by the contact pairs of the pile-up 22. Conversely, on withdrawing the relay M from its association with the mounting plate H, the base plate l9 will free the plunger 25 which may respond to the urge of the resilient elements 2- which in sliding the plunger 26 leftwardly will close the contact pairs and the circuits associated therewith before the contact elements iii of the relay are removed from electrical association with the jack assembly l2.

In Fig. 3 is shown schematically the circuits associated with the line relay arrangement connected to the terminals Ilia through 30. Those circuit elements of Fig. 3 which are associated with the jack assembly 52 are enclosed within one broken line rectangle and in a similar fashion those elements which are part of the line relay It have been indicated within another.

A normally closed telegraph line L over which code signal combinations are transmitted through a series of telegraph substations (not shown) is connected. to line terminals Ito and l3b at the substation indicated schematically in Fig. 3. An auxiliary circuit 33 including contact pairs at adapted to be operated by the plunger 2% is also connected to the terminals l3a and i311. The elements [2a and l2?) of the jack assembly are electrically connected to the terminals HM and 132), respectively, and are adapted to receive the contact elements 16a and 16b, respectively, carried by the base plate of the relay M. The line winding of the line relay I4 is associated with the contact elements Ilia and ltb. A second auxiliary circuit 35 is connected across terminals I30 and 13d and includes the second contact pair Also connected to terminals Ito and ltd through the jack elements 520 and HM and contact elements 50 and ltd is the armature 3! and marking contact M of the line relay M. A battery 33 and selector magnet 38 of any desired signal responsive apparatus are connected in series across the terminals [to and ltd. The armature 3'! and spacing contacts of the line relay [4 are connected between contacts 13d and [32, respectively, through the agency of the jack elements 12d, Hie, and contact elements Hid and Ice. The battery to and a load resistance 40 are also connected across the terminals Kid and Lie. A biasin Winding ll of the line relay M is connected to battery 33 through the contact elements N57 and lilo, jack elements l2 and Hg, and terminals ill and its, as well as a current limiting resistance 32 which keeps the current in the biasing winding to a value smaller than the line current.

It is contemplated that code signal combinations of the start-stop type will be transmitted over the line L to actuate the line relay M at each of the stations on the line and to control thereby the signal responsive apparatus through the selector magnet 39. When the line relay is placed in service in the line, as indicated in Fig. 3, the line circuit is closed through the line winding 25d thereof and the auxiliary circuits 33 and 36 are opened at their contact pairs El and 32, respectively. The first impulse of a code signal combination received at the station SI is the start impulse, a pro-current condition, and for the duration of that impulse there is no current flowing in the line or in the line Winding 34 and biasing Winding M is, therefore, eifective to position the armature 37 of the relay against the spacing contact S to complete the battery circuit througth the load resistance t and at the same time to open the circuit to the selector magnet 39, which, as is well known in the art, is effective to initiate the operation of the signal responsive apparatus for which magnet 39 is the selecting magnet.

The next succeeding five impulses, assuming that a five-unit code is employed in the particular system, are permutations of current and no-current conditions on the line L, and since the line current during the current impulses is greater than the current in biasing winding 41, the relay armature 37 is positioned against its marking contact M during the current impulse or marking signal impulses to energize the selector magnet 32. During the no-current impulses the biasing winding ll interrupts the circuit to the selector magnet 39 to (So-energize it. In this manner, the signal responsive apparatus is conditioned in accordance with the received code signal combinations. At the completion of a code signal combination, the final impulse, a stop impulse, is effective to place the relay armature 3'! against its marking contact M to energize the selector magnet 39 which is effective to interrupt the operation of the code signal apparatus and retain that apparatus in an idle condition until the reception of the next su ceeding start impulse.

When it becomes necessary for any reason, such as for the purpose of making adjustments, to remove the relay I 4 from the line, the abovedescribed relay arrangement is effective to maintain continuity of the telegraph line L. When the relay M is partly withdrawn from the mounting plate ll, springs 21;, in the manner described above, expel the switch plunger and close first the contact pair 32, inasmuch as the spacing between those contacts 23 is smaller the spacing 2e between the contacts of the pair 3!, to complete the auxiliary circuit 3'5 which supplies marking battery to the selector magnet 35. Immediately thereafter as the spring elements 24 move the plunger 23 to its extreme position, contact pair 3! is closed enabling the auxiliary circuit 33 to close the line from terminals and 63b through this auxiliary circuit to thereby maintain continuity of the line. Subsequent to the enabling of the auxiliary circuits 33 and 36 the retracting movement or" the line relay M is effective to remove the contact elements it carried thereby from electr cal connection with the elements of the jack assembly [2 so that the line relay is thereby completely removed from any electrical connection to the line.

It is necessary to condition the auxiliary circuit prior to the circuit 33 upon the removal of the line relay to assure that marking battery will be placed upon the selector magnet 39 immediately upon the removal of the relay so that the apparatus associated therewith will be maind in its idle condition. If the auxiliary circuit were conditioned first, to thus place a shunt across the line winding of relay 34, biasing winding a: would be effective to attract armature 37 of the relay and break the circuit to the selector magnet at this point. This interruption of the selector magnet circuit is equivalent to a starting signal and releases the associated telegraph apparatus for operation. That is, the selector magnet 38 would be jg-energized, which would release the signal responsive apparatus therefor for operation which, of course, is undesirable when the line relay is removed from the circuit.

When the line relay is reinserted into the line its contact elements 56 will come into electrical connection with the elements and shortly thereafter the base plate of the relay it the relay assumes its supported position in plate i! will engage and operate switch plunger to open the circuits controlled by the contact pairs reestablish the telegraph system and its ated circuits, as illustrated in Fig.

It may be seen, therefore, that with a arrangement such as is the sub'oct of tion, the telegraph line serving th 1 always closed at the terminals of arrangement, irrespective G1 the fact the relay may have been removed. Fur arrangement also insures th sive apparatus controlled by the line relay will not be released upon the removal the relay even for a moment but instead will be held in its inoperative or idle condition until a line relay been returned into electrical connection with the line and a code signal combination has been received.

Although a specific embodiment of this invention'has been disclosed in the drawing and described in detail, it is to be understood that the invention is not to be limited by this disclosure, but is capable of many modifications and rearrangements of parts, and accordingly is to be limited only by the appended claims.

What is claimed is:

1. In a telegraph system, a station, a plurality of terminals at said station, a telegraph line connected in series with a pair of said terminals, an auxiliary circuit associated with said pair of 7 terminals to maintain continuity of said line at said station, a selector magnet at said station connected to another pair of said terminals, a second auxiliary circuit associated with said other pair of contacts to maintain a predetermined condition on said selector magnet, a line relay removably associated with said pairs of terminals, and

means actuated by said relay upon the removal thereof from said pairs of terminals to disable said auxiliary circuits to close said line through said line relay, and to connect said selector magnet in circuit with said line relay whereby said selector magnet is conditioned in response to signals received over said line.

2. In a telegraph system, a substation, a telegraph line connected to said substation, a line relay removably connected in said line at said substation, a selector magnet at said substation connected in circuit with said relayto respond to signals received over said line, auxiliary circuits for said line and said selector magnet, and means operable upon removal of said line relay from electrical connection with said line to condition said auxiliary circuits, to maintain continuity of said line at said substation, and to maintain a predetermined condition on said selector magnet.

3. A telegraph system comprising a telegraph line, a substation associated with said line, a line relay at said substation removably connected to said line, signal responsive apparatus at said substation conditioned by said line relay in response to signals received over said line, auxiliary circuits one for said line and one for said signal responsive apparatus, and means operable upon the act of removing said relay and before said relay isout of electrical connection with said line to condition said auxiliary circuits, to maintain the line circuit to said substation uninterrupted, and to establish a predetermined condition of said signal responsive apparatus.

4. In a telegraph system, a telegraph line, a substation associated with said line, first circuit means at said substation operable to maintain said line continuous at said substation, signal responsive apparatus at said substation, second circuit means at said substation operable to maintain a predetermined condition on said signal responsive apparatus, a line relay to be removably connected in said line at said substation, and means operable to disable said first and second circuit means, to connect said relay into said line, and'to place said signal responsive apparatus in circuit with said relay whereby said line is maintained continuous through said relay and said signal responsive apparatus is conditioned by said relay in accordance with signals received over said line.

5. In a telegraph system, a telegraph line, a substation associated with said line, first circuit means at said substation operable to maintain said line continuous at said substation, signal responsive apparatus at said substation, second circuit means at said substation operable to maintain a predetermined condition on said si nal responsive apparatus, a line relay to be removably connected in said line at said substation, and circuit controlling means operated by said relay in connecting said relay into said line to disable said first and second circuit means, to establish line continuity through said relay, and to place said signal responsive apparatus in circuit connection with said relay to be controlled thereby in accordance with signals received over said line, said circuit controlling means being operated upon the act of removing said relay from said line but before said relay is out of electrical association with said line to enable said first and second circuit means.

6. In a telegraph system, a telegraph line, a substation associated with said line, first circuit means at said substation operable to maintain said line closed at said substation, signal responsive apparatu at said substation, second circuit means at said substation operable to maintain a predetermined condition on said signal responsive apparatus, a line relay to be removably connected in said line, and switching means operable by said relay upon its connection in said line to disable said first circuit means and said second circuit means, to close said line through said relay, and to establish an electrical connection between said relay and said signal responsive apparatus to render said apparatus responsive to the operation of said relay in accordance with signals received over said line, said switching means being operable upon the removal of said relay from said line to enable in order said second circuit means then said first circuit means before said relay is removed from electrical connection with said line.

'7. A line relay arrangement for a telegraph system comprising a relay mounting plate, a plurality of terminals on said plate, a plurality of normally closed contact pairs carried by said plate each contact pair including a spring ele ment, a plunger slidably carried by said mounting plate in alignment with said contact springs, and a line relay having contact elements to be removably supported by said mounting plate in electrical connection with said terminals, said relay being operable when supported by said plate to engage said plunger and project it into engagement with said contact springs to open said contact pairs.

8. A line relay arrangement for a telegraph system comprising a relay mounting plate, a plurality of terminals on said plate, a plurality of normally closed contact pairs carried by said plate, each contact pair including a spring element, a contact operating plunger carried by said plate, said plunger being cammed out of contact operating engagement with said contact pairs by said spring elements, a line relay including contact elements, means for removably supporting said relay by said mounting plate with its contact elements in electrical connection with said terminals, said relay being operable when supported by said mounting plate to project said contact operating plunger into contact operating relationship with respect to said spring elements to operate said contact pairs.

9. A line relay arrangement for a telegraph system comprising a relay mounting plate, a plurality of terminals on said plate, a plurality of normally closed contact pairs carried by said plate, each contact pair including a resilient element, a contact operating element operable to open said pairs, a line relay including contact elements, and means for removably supporting said relay by said plate with its contact elements in electrical connection with said terminals, said relay when supported by said plate being operable to project said contact operating element into contact operating relationship with respect to said contact pairs, and said resilient elements being operable when said relay i removed from said plate to cam said contact operating element out of contact operating relationship with respect to said contact pairs.

10. A line relay arrangement for a telegraph system comprising .a relay mounting plate, a plurality of terminals on said plate, a plurality of normally closed contact pairs carried by said plate, each contact pair including a resilient member, a switch member operable to open said contact pairs, a line relay including contact elements, and means for removably supporting said relay by said plate with its contact elements in electrical connection with said terminals, said relay when supported by said plate being operable to actuate said switch member against the force of said resilient members to open said contact pairs, and said resilient members being operable to actuate said switch member out of contact operating position and to close said contact pairs as said line relay is removed from said plate and while said contact element and said terminals remain in electrical connection.

11. A line relay arrangement comprising a relay mounting plate, a plurality of terminals on said plate, a plurality of normally, closed contact pairs carried by said plate, each contact pair including a resilient member, a switch member operable to open said contact pairs, a line relay including contact elements, and means for removably supporting saidv relay by said plate with its contact elements in electrical connection with said terminals, said relay when supported by said plate being operable to actuate said switch member to open said contact pairs, and said resilient members being operable to actuate said switch members to close said contact pairs in a predetermined sequence as said line relay is removed from said plate and while said contact elements and said terminals remain in electrical connection.

KIMMEL A. SYLVESTER. 

